$\dfrac{4}{5} \div \dfrac{7}{9} = {?}$
Answer: Dividing by a fraction is the same as multiplying by the reciprocal of the fraction. The reciprocal of $\dfrac{7}{9}$ is $\dfrac{9}{7}$ Therefore: $ \dfrac{4}{5} \div \dfrac{7}{9} = \dfrac{4}{5} \times \dfrac{9}{7} $ $ \phantom{\dfrac{4}{5} \times \dfrac{9}{7}} = \dfrac{4 \times 9}{5 \times 7} $ $ \phantom{\dfrac{4}{5} \times \dfrac{9}{7}} = \dfrac{36}{35} $